This invention relates to the detection of faults along an electric overhead traveling crane runway and more particularly to a system for detecting the location of rail conditions that cause excessive wear of crane wheels and rails.
Excessive wear of the rails and wheels of electric overhead traveling cranes may be caused by a number of undesirable conditions such as settled supporting columns, poor rail splices or misaligned rails. Such defects are usually identified by detailed inspections of anchors, bolts, rail end joints and may also require careful measurements of rail spacing, elevation and alignment. Such inspections usually require a lengthly period when the crane or cranes must be out of service and often have questionable value since so much of the inspection is based on the judgement of the inspector. In addition, such inspections require walking the length of runways, a task requiring extreme care by the inspector. Once an inspection has been made and defects discovered and corrected, there is no simple method for determining whether the corrective efforts were completely satisfactory other than another more tedious inspection.
In accordance with my invention, axial vibrations of crane wheel drive shafts are detected and recorded graphically as the crane travels along the runway. The locations of the vibrations are graphically correlated with runway supporting column locations and rail splice locations and the locations where vibration amplitudes are greater than an acceptable level are an indication of the potential presence of an undesirable condition which may cause excessive wear. The test method is relatively simple, fast, repeatable and provides a permanent record. The location of the excessive vibration amplitudes also provides some direction in determining the nature of a particular condition causing the vibrations.
It is therefore an object of my invention to provide an accurate and fast method for determining the location of faults along an electric overhead traveling crane runway that cause wear on the crane wheels.
Another object is to provide apparatus for permanently recording the location and extent of such faults.